Re: How to recover when monitor goes blank.
Ram Ramesh composed on 2024-06-20 22:58 (UTC-0400): >> Did you try 'e' as I suggested, or read that page? From there: >> [quote] >> 'e' will force the display to be enabled, i.e. it will override the detection >> if a display is connected. >> [/quote] > Ok, I will try it, but that is a reboot. I guess if I booted with that > switch, it will always be on and I would not reach a point of blank > screen. Make sense. > I just do not like forcing resolution, but better than broken display. The foibles of life complicated by a KVM switch. :p I hope it does what it claims. If not, I suppose you could connect both Debian PC and laptop to display at the same time, and use the display's input switch instead of the KVM for video out. -- Evolution as taught in public schools is, like religion, based on faith, not based on science. Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata
Re: How to recover when monitor goes blank.
Did you try 'e' as I suggested, or read that page? From there: [quote] 'e' will force the display to be enabled, i.e. it will override the detection if a display is connected. [/quote] Ok, I will try it, but that is a reboot. I guess if I booted with that switch, it will always be on and I would not reach a point of blank screen. Make sense. I just do not like forcing resolution, but better than broken display. Regards Ramesh
Re: How to recover when monitor goes blank.
Ram Ramesh composed on 2024-06-20 17:43 (UTC-0500): >> Not to recover, but to perhaps prevent, via kernel cmdline, one can direct >> the >> kernel which framebuffer mode to force-enable with video=, e.g.: >> video=2560x1440@60e >> https://www.kernel.org/doc/Documentation/fb/modedb.txt > I think kernel thinks that no monitor is attached or KB is present. I > want to remote login and tell it to look again and find them. > It appears like there is no magic incantation exists for that. I was > hoping a write to /sys or /proc file will do the trick, but no such > thing seem to exists. Did you try 'e' as I suggested, or read that page? From there: [quote] 'e' will force the display to be enabled, i.e. it will override the detection if a display is connected. [/quote] The way I read it, if it doesn't work, it's yet another kernel bug, because it should - prevent - not fix. -- Evolution as taught in public schools is, like religion, based on faith, not based on science. Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata
Re: How to recover when monitor goes blank.
Not to recover, but to perhaps prevent, via kernel cmdline, one can direct the kernel which framebuffer mode to force-enable with video=, e.g.: video=2560x1440@60e https://www.kernel.org/doc/Documentation/fb/modedb.txt -- Evolution as taught in public schools is, like religion, based on faith, not based on science. Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata I think kernel thinks that no monitor is attached or KB is present. I want to remote login and tell it to look again and find them. It appears like there is no magic incantation exists for that. I was hoping a write to /sys or /proc file will do the trick, but no such thing seem to exists. Regards Ramesh
Re: How to recover when monitor goes blank.
Ram Ramesh composed on 2024-06-19 15:45 (UTC-0500): > I have my monitor, keyboard and mouse shared through a KVM switch. > One host is Linux Debian bookworm 12.5 and another is laptop running > Windows 11. When I leave KVM on the laptop side for extended period I > have issues switching back to Debian side. When I switch, the screen is > blank and KB does not respond as if Debian is running headless. I had to > remote login and reboot Debian side with KVM locked on this side to get > back the monitor/KB. This happens regardless of whether I am in Xorg or > VT. I do not know how to force Debian/Linux to check for monitor/KB > again after extended period of disconnect when it has assumed it is > running headless. Any solutions? Not to recover, but to perhaps prevent, via kernel cmdline, one can direct the kernel which framebuffer mode to force-enable with video=, e.g.: video=2560x1440@60e https://www.kernel.org/doc/Documentation/fb/modedb.txt -- Evolution as taught in public schools is, like religion, based on faith, not based on science. Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata
Re: How to recover when monitor goes blank.
My Debian machines have Xfce. I configure Applications Menu -> Settings-> Power Manager -> Display -> Display power management -> Off. David This is not a dpms issue. This is the OS thinking that it is not attached to a monitor/KB. I can remote login and remove dpms any time. Besides this happens in a VT also where there is no xfce. I just do not know how to tell Linux/OS that a monitor and kb is attached and it should look for enabling the respective drivers. I thought xrandr is the way to go, but that is only when Xorg is running and not when we are at a VT login prompt. Regards Ramesh
Re: How to recover when monitor goes blank.
On 6/19/24 13:45, Ram Ramesh wrote: Hi, I have my monitor, keyboard and mouse shared through a KVM switch. One host is Linux Debian bookworm 12.5 and another is laptop running Windows 11. When I leave KVM on the laptop side for extended period I have issues switching back to Debian side. When I switch, the screen is blank and KB does not respond as if Debian is running headless. I had to remote login and reboot Debian side with KVM locked on this side to get back the monitor/KB. This happens regardless of whether I am in Xorg or VT. I do not know how to force Debian/Linux to check for monitor/KB again after extended period of disconnect when it has assumed it is running headless. Any solutions? Regards Ramesh My Debian machines have Xfce. I configure Applications Menu -> Settings -> Power Manager -> Display -> Display power management -> Off. David
How to recover when monitor goes blank.
Hi, I have my monitor, keyboard and mouse shared through a KVM switch. One host is Linux Debian bookworm 12.5 and another is laptop running Windows 11. When I leave KVM on the laptop side for extended period I have issues switching back to Debian side. When I switch, the screen is blank and KB does not respond as if Debian is running headless. I had to remote login and reboot Debian side with KVM locked on this side to get back the monitor/KB. This happens regardless of whether I am in Xorg or VT. I do not know how to force Debian/Linux to check for monitor/KB again after extended period of disconnect when it has assumed it is running headless. Any solutions? Regards Ramesh
